The present invention relates to a saber saw tool having a motor drive with a reciprocating driver means for a tool having a mass equilibrating body and a device for converting a rotary movement of the motor drive into a reciprocating movement of the reciprocating means along a first movement axis and an opposite movement axis. In this tool the mass equilibrating body is guided at an angle α to the reciprocating driver means such that the movement axis runs constant at an angle to the movement axis of the reciprocating driver means. This type of saber saw tool is a saber saw or a jigsaw, wherein a saw blade can be displaced in a reciprocating movement using a driving arrangement.
In saber saw tools a counterweight is provided for balancing the unbalance of the reciprocating means such as a stroke rod, which is operated with the reciprocating means in the direction opposite to the drive train.
U.S. Pat. No. 6,634,107 discloses this type of weight compensation in a driving arrangement of a reciprocating saber saw, which can be operated in an oscillating reciprocating mode or in a purely reciprocating mode. In the aforementioned driving arrangement, a counterweight is operated by a driven shaft opposite to a stroke rod. In oscillating operation of the oscillating reciprocating saw, the direction of movement of the stroke rod in the course of the oscillating movement is brought intermittently into a tilted position relative to the direction of movement of the counterweight. In pure reciprocating operation, on the other hand, the directions of movement of the stroke rod and the counterweight run parallel to each other.
In U.S. Pat. No. 6,634,107, with the movement of the stroke rod and, thereby, of the plunger and counterweigh parallel to each other and with both the plunger and the counterweight having centroids that agree with each other, no torque and no immanent contact force, which can be superimposed on the contact force applied by the saw user, is generated during the pure reciprocating mode. With the cutting performance being determined only by the contact force applied by the user, the cutting performance of the saw in pure reciprocating mode is rather low.